This invention relates to an antenna and a wireless communication apparatus, more particularly to a low profile three-dimensional antenna and a wireless communication apparatus provided with the same.
FIG. 1 shows a conventional planar monopole antenna 100 of U.S. Pat. No. 7,193,566. The conventional planar monopole antenna 100 includes a substrate (S) having a surface (S1), a ground (G), a radiator (R) and a coaxial cable (W).
The ground (G) is formed on the surface (S1) of the substrate (S) and includes a side (G′), and first and second sleeves (G1, G2) that are parallel to each other and that extend from the side (G′) along an axis (Z).
The radiator is longitudinal along the axis (Z), is formed on the surface (S1) of the substrate (S), and is adjacent to the side (G′).
The coaxial cable (W) includes a signal wire (W1) electrically coupled to a feed end (RF) of the radiator (R) adjacent to the side G′ of the ground G, and a ground wire (W2) electrically coupled to the side (G′) of the ground (G) and enclosing the signal wire (W1).
When the conventional planar monopole antenna 100 operates in the range of 400-900 MHz, a length of the radiator (R) is already 14 cm, bringing an overall length (L) of the conventional planar monopole antenna 100 (i.e., the length of the radiator (R) plus a length of the ground (G) greater than 14 cm, that is, greater than ¼ of a wavelength corresponding to a central frequency.
As shown in FIG. 2, although the planar monopole antenna 100 is relatively small in thickness and light in weight, in practice, since the conventional planar monopole antenna 100 has to be erected on a surface (B) of a device for efficient radiation, a profile thereof in a direction along the axis (Z) is relatively high.